The STMicroelectronics VIPER53SPTR-E is a monolithic offline flyback switcher from the VIPER™ series, integrating the PWM controller and a 620 V avalanche-rugged power MOSFET in a single PowerSO-10 package with an exposed bottom pad for thermal management. It delivers up to 65 W in a flyback topology, switching at up to 300 kHz, and includes built-in fault protections — current limiting, over-load, over-temperature, and short-circuit — so the external component count stays low.
The 65 W power rating defines the output capability for a flyback stage. The 620 V breakdown voltage gives headroom for universal AC input with derating for line transients. The switching frequency range up to 300 kHz lets you shrink the transformer core and output filter. The 11.5 V startup voltage and 8.4 V to 19 V Vcc range are typical for self-supplied offline converters.
It is ROHS3 compliant, which simplifies compliance for EU and global markets. The base product number is VIPER53, and the -E suffix denotes the lead-free, ROHS3 version. No official replacement has been issued, and the part is not marked NRND or obsolete.